Shock-absorbing support for radiotube mounts



Nov. 7, 1939. w. L. KRAHL SHOCK-ABSORBING SUPPORT FOR RADIO-TUBE MOUNTS Filed March 10, 1 937 max/21% INVENTOR Patented Nov. 7, 1939 SHOCK-ABSORBING SUPPORT FORRADIO- TUBE MoUN'rs.

Walter L. Krahl, Swampscott, Mass., assignor to Hygrade Sylvania Corporation, Salem, Mass, a corporation of Massachusetts Application March 10, 1937, Serial No. 129,993

6 Claims.

This invention relates to electric discharge tubes and more particularly to shock-absorbing supports for the electrode assembly or mount of a radio tube and the like.

A principal object of the invention is to provide a simple, inexpensive and thoroughly reliable shock-absorbing support for a radio tube mount.

A feature of the invention relates to a flexible wire clip which is readily attachable as by welding, to an electrode side-rod or other similar part of a radio tube mount.

Other features'and advantages not specifically enumerated will be apparent after a consideration of the following detailed description and the appended claims.

In the drawing,

Fig. 1 is an elevational view, partly in section, of a radio tube embodying the invention.

Fig. 2 is a top, plan view of the mount of Fig. 1.

While the invention will be illustrated as embodied in one well-known form of radio tube having a glass enclosing envelope, it will be understood that it is not-limited thereto but is also applicable to so-called metal tubes. Likewise since the invention is not concerned with any particular number or arrangement of electrodes in the mount, only sllfilcient parts of a mount are shown to enable the invention to be understood. Accordingly, in Fig. 1 the numeral l represents a glass enclosing envelope preferably of the ST shape, that is with a cylindrical dome portion 2 at the top. Sealed into the envelope I is a reentrant stem or base 2 wherein are insulatingly supported the various lead-in and support wires 4 to I ll inclusive. The mount or electrode assembly may comprise any number of electrodes but merely for purposes of explanation a mount of the triode type is shown, and comprises an indirectly heated cathode l, a grid l2 supported on the side-rods l3, l4, and a tubular plate or anode l5 supported on the side-rods 4 and H). For the purpose of maintaining the spacial relation of the various electrodes, upper and lower insulator spacer members it and H are provided, these spacer members being of mica, ceramic or the like and having a series of perforations as shown in Fig. 2 to receive the ends of the various siderods as well as the ends of the cathode sleeve and said spacers being secured to the support rods 4 and H) as by eyelets 25. Preferably the mount is supported so that it extends partly within the cylindrical or dome portion of the bulb.

As shown clearly in Fig. 1, the plate side-rods 4 and I!) extend upwardly beyond the upper spacer member I 6 and in order to.'support the upperend of the mount in a shock-proof manner from the dome 2, there are provided two flexible wire clips l8, 19 of phosphor-bronze or similar spring metal. Each of the said clips is provided 5 intermediate its ends with an offset portion 20 which is adapted partially to surround the, upper end of the associated plate side-rod. Preferably the clips are fastened to the side-rods by welding thereto at the said offset portions. As shown each clip is welded to its side-rod so that the offset portion 20 is inclined at an angle of approximately 45 degrees to the vertical axisof themount, and preferably so that the twolegs 2|, 22 of each offset, engage the edge of the mica spacer l6. The free end portions of each clip, when the mount is assembled within the bulb, extend outwardly beyond the mica and being normally longer than the space between the edge of the mica and the inner wall of the dome 3, are flexed to a substantially vertical position as shown in. Fig. 1 so as to conform themselves to the shape of the dome. Preferablmalthough not necessarily, the said free ends are rounded and slightly w curved inwardly towards each other. It will be understood of course that the clips are welded to the plate side-rods prior to assembling the-mount within the bulb so that the said clips center the mount with respect to the bulb, but are not disturbed during the usual pull-down operation of sealing the mount into the bulb. By this arrangement, therefore, the wire clips each provide a pair of flexible supports for the upper end of the mount with respect to the bulb, and the ends 23, 24 adapt themselves readily to bulbs of different diameters. Furthermore, the legs 2|, 22 of l each clip are normally of more uniform stiffness than mica springs, and the mounts will therefore be more accurately centered in the domes 3 of the bulbs I.

Various changes and modifications may be made in the disclosure without departing from the spirit and scope of the invention.

What I claim is:

1. In combination an enclosing envelope having a cylindrical portion, an electrode assembly mounted within the envelope and extending at least partially into said cylindrical portion, said assembly having a pair of spaced vertical uprights, an electrode spacer of insulating material bridging the upper ends of said uprights and means to resiliently support said assembly in spaced relation to said cylindrical portion the last-mentioned means comprising a pair of metal springs each having an ofiset portion embraci5 ing and welded to an associated one of said siderods with portions intermediate the ends engaging the edge of said insulator spacer and with the end portions in contact with said enclosing envelope.

2. In combination an enclosing envelope having a cylindrical portion, a radio tube mount within said envelope and extending at least part way into said cylindrical portion, said mount including an insulating electrode spacer extending transversely across said cylindrical portion and a pair of side-rods extending through said spacer, and means to resiliently support said mount in spaced relation to said cylindrical portion, the last-mentioned means comprising a pair of bifurcated wire springs each having an offset portion fastened toan associated one of said siderods, said springs being inclined downwardly at an angle to said side-rods and having their bicurcated ends in contact with the said cylindrical portion.

3. In combination an enclosing envelope having a cylindrical portion, a radio tube mount within said envelope and extending at least part way into said cylindrical portion, said mount including an insulating electrode spacer extending transversely across said cylindrical portion and a pair of side-rods extending through the spacer, and means to resiliently space said mount from the cylindrical portion of the envelope, the lastmentioned means comprising a pair of bi-furcated metal springs each having an offset portion fastened to an associated one of said side-rods, each spring being inclined downwardly with respect to the mount and being retained in flexed form by having the bi-furcated portions in engagement with the edge of the spacer and the free ends in contact with the said cylindrical portion.

4; In combination, an enclosing envelope having a cylindrical portion at its upper end, a radio tube mount Within said envelope and extending at least part Way into said cylindrical portion, said mount including a disc of insulation extending transversely across said cylindrical portion and a pair of side rods extending through said spacer to support the same, and means to resiliently space said mount from the envelope, the last-mentioned means comprising a pair of metal springs each spring being fastened to a corresponding side rod and having a portion intermediate its ends in engagement with the edge of said disc and the two ends of each spring extending beyond said disc into engagement with said cylindrical portion, said springs being retained in flexed condition by reason of their engagement with the disc edge and the said cylindrical portion.

5. In combination, an enclosing envelope having a cylindrical portion at its upper end, a radio tube mount within said envelope and extending at least part Way into said cylindrical portion, said mount including a disc of insulation extending transversely across said cylindrical portion and a pair of side rods extending through said spacer to support the same, and means to resiliently space said mount from the envelope, the last-mentioned means comprising a pair of metal springs at opposite sides of said disc each spring having its central portion fastened to one of said side rods and having a portion intermediate its ends in engagement with the edge of said disc, the two ends of each spring extending beyond the disc into engagement with said cylindrical portion, said springs being retained in flexed condition by reason of the engagement with the edge 'of the disc and said cylindrical portion.

tube, each of said springs also engaging a corresponding edge of said strip.

WALTER L. KRAHL. 

